Conventional roller clutches have a plurality of cylindrical rollers that are located in wedging pockets formed between a cylindrical pathway of one clutch race and a series of sloped cam ramps on another clutch race. A cage fitted to one race usually has side rails of some type to confine the ends of the rollers and prevent them from moving axially out of the annular spaced between the races. Individual energizing springs continually urge each roller up the cam ramp to a ready position. Because of eccentricities between the races and other factors, the rollers move circumferentially back and forth within the wedging pockets during clutch operation.
Typically, there is no significant limitation on circumferential roller travel by the cage or the springs in a conventional roller clutch, nor is there any particularly effective control of the roller's operation during overrun. The need for free roller travel makes control difficult especially at high speeds.
The ability of prior art roller clutches to accommodate high speeds has been improved by the use of roller control cars which carry the individual rollers and guide the rollers as they are adjusted relative to the inner and outer races during operation. Each roller has an individual control car that completely surrounds the roller closely enough to retain it securely. Patents that consider roller control include U.S. Pat. Nos. 4,821,856; 4,893,702; and 4,993,528.
Such roller car constructions, however, are complicated and add to manufacturing costs.